基于分频带传输的单载波水声通信技术研究

针对正交频分复用技术的峰均功率比较高且对多普勒频偏敏感等问题,提出基于分频带传输的单载波水声通信技术,为水下高速通信领域提供了一种可行性方案。该方案将相对较宽的通信频带划分为若干子带,在每个子带间插入保护频带,以消除载波间干扰。开展了水声通信试验,发射换能器频带被划分为两个子频带,每个子带带宽为2.25 k Hz,子频带保护间隔为0.75 k Hz,载波频率分别为3 k Hz和6 k Hz.采用被动时间反转镜联合判决反馈均衡器的接收机结构抑制码间干扰,当映射方式为8相移键控时,3 km、5 km和7 km距离上的试验数据均实现了通信速率为9 kbit/s的低误码率数据传输,验证了该系统的稳健性。

Research on Single Carrier Underwater Acoustic Communication Based on Multiband Transmission

For the high peak-to-average power ratio and the sensitivity of orthogonal frequency division multiplexing system to Doppler shift, a single carrier underwater acoustic (UWA) communication method based on multiband transmission is proposed, providing a feasible approach for high-rate UWA communication. The communication band is divided into some sub-bands with several kilohertz in bandwidth, and a guard band is inserted between sub-bands to eliminate inter-carrier interference at the receiver. A UWA communication experiment was conducted at sea. The available band is divided into two sub-bands, of which has 2.25 kHz in bandwidth and a 0.75 kHz guard band, and the carrier frequencies are 3 kHz and 6 kHz, respectively. Passive time reversal mirror combined with decision feedback equalizer is used to suppress inter-symbol interference. Transmissions of test data at communication distances of 3 km, 5 km, and 7 km are implemented at low bit error rate with communication rate of 9 kbit/s when modulated by 8-PSK, proving the effectiveness and robustness of the proposed method.